Social interaction was the way which sentient beings talked and acted with each other.
In 3189, Michael Burnham attempted to be a teacher in the dynamics of social interactions for Su'Kal. When Su'Kal asked why he should learn this subject, Burnham replied that it was "incredibly important" for individuals to be connected with others and that these connections helped to sustain them. In addition, by learning about social interactions, Su'Kal could be prepared for the time when he talked to someone else, even someone unexpected, in the future. (DIS: "Su'Kal")